Improved mode of preventing the potato-rot



UNITED STATES ATENr rrrce.

f CHRISTOPHER CORY, OF LIMA, INDIANA.

Specification forming-part of Letters Patent No. 43,292, dated June 28,1864 To all whom it may concern:

Be it known that I, CHRISTOPHER 001m, of Lima, in the county of LaGrange and State of Indiana, have invented new and efficient Methods ofRetarding, (lounteractin g, and Remedyin g the Potato Disease and I dohereby declare that the following is a full, clear, and exactdescription thereof.

The nature of my invention consists in counteracting, mitigating,'andremedying the potato disease known as the potato-rot, and also incounteracting and retarding its pro: grass.

The potato-rot, as is most clearly demonstrated by many observations andexperiments continued through a succession of near seventeen years, isoccasioned primarily by insects and animalcules and, secondly, it isenlarged and still further propagated by its own infective influenceswhen existing in circumstances favorable. for the decay of vegetablematter. As to the primary causes-41. 6., insects and animalcules, theseoperate on theleaves, vines, and the roots, and especially on and withinthe tubers themselves. They are extensively planted withthe seed potato,being within it, and are grown and perpetuated with the potato crop.Hence the more diseased the seed potato the more diseased the potatocrop, other things being equal. Soil, climate, and seasons have much todo to increase or retard said disease. A clay soil, from its beingcompact and moist, favors the increase of the animalcules themselves,and also prevents the desirable escape of the deranged fluids and gasesof the diseased potato. So, also, a hot, sultry, wet period,after theanimalcules are collected inside of the tubers, is favorable for theirrapid increase in number and in efiiciency. The wounds also inflicted bythem in this wet, hot, sultry period become, by reason of the extraconfinement, moisture, and heat, more corrupt and infective. Hence thegreater prevalence of the disease at different times and in differentseasons. Potatoes closely confined in large quantities and in warm,moist, sultry locali ties, if but moderately affected at first, canhardly escape complete destruction if they are long continued in saidcondition. The primary causes will multiply in numbers vastly and thework of destruction will progress with arapidity known only to thisparticular malady.

; It is thought by some who admit the exist,

ence of insects and animalcules in diseased potatoes that they areconsequents rather than causes of said disease; but it is evident fromrepeated observations that the first symptoms of this disease in thetubers are found in the form of small punctures in spots on the surface,while in all other respects the potato has a healthy appearance. Thesespots, under favorable circumstances for the increase of the disease,are found also to deepen and widen, and ultimately to corrupt and throwout tainted effiuvia, and otherwise give unmistakable evidence of theregular progress of this noted potato disease, and yet in themeantimethe other parts and portions of the potato may present a healthyappearance. For this local affection there must be some efficientlocalcause. If the cause producing these local effects be in the vine or rootor nature of the potato, or

in the sickliness ofthe vine or tubers, or both, or a if it be in thedegeneracy of the plant, then why is this malady local, and notspreadequally alike over the whole potato? ()n the other hand, these affectedparts often give other corresponding proofs of much importance in thecase. The said punctures are often followed by still other signs ofliving agencies, such as additional perforations, refuse matter, andnumerous sloughed-off coverings of the insects themselves. Besides,these insects, notwithstanding all the difficulty of their visibilityfrom their minuteness, color, and concealment, have been and may stillbe seen in sufficient number to convict them of the depredations sostrongly suspected by these facts just enumerated. They, with theirassociates or their ancestors, perforated the potato. They caused thefestering and infectious wounds. They putinto active operation thiswhole work of destruction so bitterly complained of throughout our land.These identical depredators may often be brought from their concealmentand made to pass in full view before the eye, assisted by suitableoptics. My own first discovery was in the season of 1847.

My potatoes, grown on a rich prairie soil, were found badly infectedwith the true, -genuine potato-rot. In harvesting them the potatoes weretaken from the hill and left scattered onthe ground to dry. 0n theoccasion referred to the middle of the day was warm and pleasant and theafter part suddenly chilly. In gathering these potatoes in the cool ofthe day numerous light specks, strongly contrasting with the dark potatoand earth, were found on them, and especially in and around theiraffected parts, which, when submitted to close inspection under amagnifying glass, were found to be animalcules of the maggot form. Fromtheir position and all the attending circumstances there could be nodoubt but they were from the wounds of the diseased potatoes, and theywere in suflicient numbers to induce the belief thatthey had causedthese said wounds, from which they had been incautiously attracted bythe light and heat of the sun. The sudden chill, which amounted tonearly a frost, had prevented their timely return to theirfeeding-ground and hiding-place. From this starting-point I have madenumerous other experiments and observations equally successful andconclusive. In the course of these experiments I have taken occasion toelicit these animalcules and other insects from diseased potatoes and togive limited exhibitions of them to some of the literati of our country,including Professor Henry, of the Smithsonian Institute; Marshel P.Wilder,then president of the United States Agricultural Society;Professor Harris, of Cambridge University, and others. Some of theseinsects shown to the gentleman last named were pronounced by him to beof the aphis species. On another occasion, while exhibiting theseinsects to the president and several of the professors of the New YorkState Normal Institute at Albany,

' one of the said insects brought forth its living offspring while underthe microscopic inspection of the president. This was in the spring of1856. The potatoes thus inspected were gathered but a few minutes beforefrom one of the vegetable stores of that city, and gave all the usualsigns of the potato-rot, together with a full supply of these primaryagents in attendance and ready to perfect the work of destructionhitherto so successfully commenced and prosecuted by them.

In the course of my experiments I have examined diseased potatoes grownin the Eastern, Middle, Western, and Southern States, and also inEngland, and find that the general appearances of this disease are thesame irrespective of the locality of the growth ofthe potato. Thosegrown on the English soil and brought over in one of their steam-packetswere no less charged with numerous living insects. The wounds inflictedand occupied by them were of the same appearance and gave the same,usual, unmistakable signs oftheir living origin.

The method that I have usually adopted of alluring these insects fromtheir concealment is to place the diseased portion of the potato in thefull light and heat of the sun some fifteen minutes or more. I thenexamine the surface of the wound in the full light of the sunwith aglass having strong magnifying powers. In this way they can usually bedetected by a skillful operator, notwithstanding their minuteness, theirsameness of color with the potato, and their usual concealment below itssurface.

The central cavity sometimes noticed in large potatoes probably does notbelong to the potato disease properly, but may be rather owing to theirmore vigorous and rapid growth. The dark spots and streaks also in somediseased potatoes lying back and still deeper in than the punctures andwounds hitherto spoken of may proceed either from the extended movementof the animalcules into those parts, or they may be occasioned by theinfecting influences of the deranged fluids and gases from the adjacentafiected parts of said potatoes. Either might be a sufficient cause forthese defects. Writers on the subject have also noticed numerous fungiin connection with the potato-rot. to the fungi. Butthen what producedthe fungi that produced the rot? This fungus existence, both on thevines and on the tubers,

seems easily accounted for as a natural derangement of the sap or fluidby reason of small and numerous punctures by these insects alreadyreferred to, causing the outflowing ot'- thejuice or sap and itsappropriation to this very species of work. 0f the dry potato-rot I haveseen but little written explanatory of its phenomenon. strange workindeed, and yet, when rightly understood, the process'of operation andthe result are equally simple and natural. These potatoes in the moreearly stages of their dis- A them the dislodged fluid intercepting theirpathway. Let this be often repeated and in different parts of thepotato, as has been frequently seen, and let the other usual process ofdrying the fluid of the potato be continued,

and soon the dry-rot will be most fully developed.

In relation to the branch of the potato disease as exhibited .in thedeadened spots on the leaves and in the withering and drying of thevines, it may all be disposed of in few words and on the same principlesas above presented.

These affected leaves have been punctured,

and their sap-i. 0., life-blood-eaten up or,

suffered to flow away. And so of the blasted vines. They have beengirdled probably near the roots, or otherwise mortally wounded, and

that, too, by the very identical living agents and their ofl'springwhich were planted with and nourished by the parent seedling. Thesedestroying agents, during the wet, hot, sultry period often referred toby the disappointed husbandmen, in which their potatoes perishedby theacre together, multiplied by the thousand and tens of thousands, andwent forth Some have attributed the wt Most have considered it a Thelarge demonstrations.

In view of these defining and explanatory remarks, two things willappear most obvious first, that these destructive agents should be asfar as practicable dispersed, neutralized, or destroyed; and, secondly,that the dislodged fluids and gases from the diseased potatoes should beremoved or counteracted. Hence the following outline: Theinsects andanimalcules are of course mostly unmanageable after the seedlingscontaining them are planted and the warm sultry season has advanced.Again, this disease is metmoredirectlyandefficiently by putting thetubers containing the living animalcules and insects into close bins, asnear air-tight as may be, or in other deposits suitably arranged, andthen with the air-pump or any other suitable implement or way let-theair be exhausted to the extent of extinguishing the life of saidinsects. The same end may be accomplished by a partial removal of theatmosphere and then inserting gases, vapors, 850., destructive of animallife; or the same'end may be attained without removing the atmosphere bypassing into and retaining among the potatoes for a sufficient timesulphurous fumes or other poisonous gases or destructive agents; or, inplace of any or all of these, electricity, by any of its appropriatemethods, may be employed. The grand ob ject is to neutralize ordestroysaid depredatorsby Whatever process or instrumentality may befound adapted or adequate to the work.

Partially-diseased potatoes may also be still further relieved bypassing cool or other currents of air, gases, or vapors, or cleansingagents over and around them to remove the disengaged gases and fluidincident to the potato-rot.

With the destruction of the above-named active living causes, and withthe removal of the dislodged fluids and poisonous gases, the potatodisease will stay its progress and the remaining unaffected portions ofthem will be found suitable for ordinary purposes.

I am aware that in the course of the last twenty years, in which thepotato disease has been so prevalent, there have been many remediessuggested and expedients tried, both in this and foreign countries, ofwhich some have been in the right direction, though without defining orapparently knowing the nature or causes of the disease or why saidtreatment was beneficial. I broadly these beneficial expedients andsuggestions; but

I do claim The invention of counteracting and remedyin g'in the tubersthemselves the potato-rot as a specific disease, caused primarily byinsects and animalcules, and, secondarily, by the infections fluid andgases of the potatoes; thus affected, by the direct destruction of theformer and by the timely regulation or removal of the latter,substantially as herein set forth.

CHRISTOPHER CORY. Witnesses:

HALLET KILBOURN, WM. MITTULE.

do not therefore claim

